Domestic "vaccine passports" are being implemented across the world as a way of increasing vaccinated people's freedom of movement and to encourage vaccination. However, these vaccine passports may affect people's vaccination decisions in unintended and undesirable ways. This cross-sectional study investigated whether people's willingness and motivation to get vaccinated relate to their psychological needs (autonomy, competence and relatedness), and how vaccine passports might affect these needs. Across two countries and 1358 participants, we found that need frustration-particularly autonomy frustration-was associated with lower willingness to get vaccinated and with a shift from self-determined to external motivation. In Israel (a country with vaccine passports), people reported greater autonomy frustration than in the UK (a country without vaccine passports). Our findings suggest that control measures, such as domestic vaccine passports, may have detrimental effects on people's autonomy, motivation, and willingness to get vaccinated. Policies should strive to achieve a highly vaccinated population by supporting individuals' autonomous motivation to get vaccinated and using messages of autonomy and relatedness, rather than applying pressure and external controls.
Keywords: COVID-19; public health; self-determination theory; vaccination; vaccine passports.